Need to Associate Multiple Document Templates with Single Service Item

It would be really useful to be able to associate multiple document templates with a single service item. For example, a promotion request service item may allow a requester to include changes to base salary, short-term incentive, and long-term incentive so the letter would not be the same for every request. It would be ideal if we could associate letter templates that accommodated the varies needs (e.g., base salary adjustment only, base salary plus LTI adjustment, etc.).